Ok, lots of pics coming up so I guess I will start with what I think is the oldest to the newest.
First up is a 222 box and the date codes from 22 Hornet and 308 boxes that have similar box design apart from the colour.

The letter number code is also stamped crudely inside the end flap. Does anyone have any idea about the key to this code?

Next is a 7x33 Sako box holding 50 cartridges and of similar design to the previous apart from the quantity and other minor differences due (I presume) to the different size box. It has a different format box code with 8 digits which seems to be the same format as a newer box (the blue 30-06 box below) with unreadable code. I think it is a transition with the older box and the newer code. Any ideas on this code format? Also what does the sticker in the top left corner signify?

The next one is a 6PPC NUPE box with Sako-Valmet branding on the back. No box code on this one which I presume is because it is not loaded ammo. Any ideas what era used this Sako-Valmet name?
This is actually the best condition box but the scanner didnt like the shiny surface much.

Last is the newest and was only purchased as ‘new’ shooting ammo last year but I think it is old stock. It retains the “111000 RIIHIMAKI” of the previous box but is now labelled SAKO OY. This box has an unreadable date code which seems to be the same or similar to the 8 digit code of the 7x33 box.

Good Luck! I think this kind of thing is very important research that the community can do. If we could gain some insight into box codes it would answer a lot of other quesitons. I have been trying to put together a lot of DWM box codes from the 1920s/1930s but can’t make heads or tails of them yet. Sure hope you can break the Sako code.

SAKO stands for ‘SUOJELUSKUNTAIN ASE-JA KONEPAJA OSAKEYHITO’ (‘Company for the manufacture of Arms for the Civil Guard’) aka SAKO OY and later OY SAKO AB. This Finnish company was founded at Riihimäki in 1927 and used the premises of the SAT company which went out of business in April 1927. SAKO commenced military ammunition production in 1928/1929 and possibly some sporting calibres with the ‘SAKO’ hs before WW2.

After WW2, SAKO introduced up to 10 new case types including modifications of the 7.62x53R Russian, 243 Win, 6.5x55 types and even several unique case types, half of which saw long term use: see : SC39-SC48

The c1946 SAKO catalog, shows either an “L” designation or a “K” designation for all loadings. The ‘K’ stands for ‘Kokovaippa’ meaning full - jacket (fmj). It is likely that the “L” refers to “Luodikko” meaning “Lead”, indicating Soft Nose (3/4 vaippainen = jacket ?). The only known example when they actually had the “L” (or “K” for that matter) in the hs, was the “SAKO — 9.3x53R/L —” (SC43) .

Evidently Lapua did load ammo for Sako (in the 1960’s at least). 1960’s Sako boxes of 6,3x53R, 6,5x52R and 9,3x53R are known with Lapua headstamps.

In 1967 SAKO became part of the large Finnish Corporation NOKIA. It introduced some new local calibres and expanded into the Export market so that by the 1970s 80% of its production went overseas. It produced more than 30 different cartridge types and is unusual in that it produces both rifles and ammunition.

From the 1980’s the title and ownership of SAKO changed often. In 1983 it became SAKO TIKKA. In 1987 it became SAKO VALMET. Later back to plain ‘SAKO’. In the year 2000 Sako became a part of the Beretta Holdings SpA an organisation that has been in operation from the year 1526. Sako is still currently producing ammunition in 2011.

That info came from a variety of sources (including company history) over two decades. Unfortunately, I cannot now cross-reference each sentence but I generally use more than one source to verify the data unless it came directly from the company itself. It is an expanded version of what was in my books.